Improvement in machine for grinding the cutters of mowing-machines



UNITED STATES PATENT OFFICE.

MILTON FOl/VKS, OF LEEDS, NEW YORK.

IMPROVEMENT IN MACHINE FOR GRINDING THE CUTTERS OF MWlNG-MACHINES.

.Specification forming part of Letters Patent No. 86,010, dated J annary 19, 1869.

To all whom it may concern:

Beit known that I, MILTON FowKs, of Leeds, in the county of Greene and State of N ew York, have invented a new and Improved Machine for Grinding the Sickles of Harvesters; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to make and use the same, reference being had to the accompauying drawings, forming part of this specification, in which- Figure l, Sheet I, represents a plan or top view of my improved sickle-grinding machine. Fig. 2, Sheet II, is a side elevation, partly in section, ofthe same.

Similar letters of reference indicate corresponding parts.

This invention relates to a new machine for sharpening the cutter-bars of mowing and reaping machines; and it consists in the arrangement of machinery for imparting combined reciprocating and rotary motion to the grindstone, so that it will move along the cutting-edges, and, at the same time, sharpen them.

The invention consists, also, in beveling the grinding-edge ofthe stone toward both sides, so that it will at once grind two diverging edges of the sickle.

The invention also consists in providing for the vertical adjustment of the stone, so that it may be lowered when worn smaller by use.

A in the drawing represents a bed-plate, made of cast-iron or other suitable material; and B IB are two posts projecting from the two corners, at one end of the plate A.

On the sides of the plate A are projecting ledges a a, which have horizontal upper edges, except in the middle, where they are inclined, as indicated by dotted lines in Fig. 2.

The middle portion, about one-third of the whole length ofthe plate A, is separated from the ends by means of two vertical ribs or low plates, b b', which are lower in their middle than at the ends, as indicated in Fig. 2.

At the corners, which are opposite to the posts B, are pivoted, to the plate A, the lower ends of swinging posts O C, in the upper ends of which are the bearings of a horizontal shaft, l). This shaft has cranks c c at its ends,

which are, by means of rods E E, connected with the upper ends of the posts B, as shown in Fig. 1.

The shaft D is provided with a crank-handle, d, or with a pulley or other equivalent device, for receiving rotary motion. j

F is a frame, resting on the outer parts of the ledges a a, and supporting in the middle a shaft, G, as shown. The frame F is, by means of rods K K, connected with the shaft D, as shown.

The shaft G has its bearings in boxes c c, that t into slots provided in the sides of the frame F. These slots are formed on arcs described from the axis of D as a center.

The boxes c can be adjusted up and down in the said slots, to raise or lower the shaft G, which, owing to the shape of the slots, is always equidistant from the shaft D.

The shafts D G are connected by means of toothed wheels f and g, as shown.

H is a grindstone mounted on the shaft G. Its grindingedge is beveled to two sides, so that it is larger in the center, as shown.

In the middle compartment of the bed a, between the two ribs b b, is placed a block, I, with a sloping surface, said block being made of rubber or other suitable material. Upon itis placed the cutter-bar, J, to be ground, the points of its teeth being on the higher part of the block I.

The following is the modas operandi: The cutter-bar is so adjusted on the block that the point where two of its teeth converge is in line with the thick middle part of the stone, as in dicated by dotted lines in Fig. l. The shaft D is then revolved. As it is by means of the rods E connected with the posts B it will, so to say, revolve on its cranks c, so as to impart, by means of the connecting-rods K K, reciprocatin g motion to the frame F and rotary motion to the shaft G. The stone will thus at once revolve and move longitudinally. It at first strikes the points of the teeth of the cutter-bar which are highest, as they have to be brought in contact with the smallest part of the stone. The farther the stone advances the more will its larger parts come in operation, until its middle strikes and grinds the lowest part of the teeththat is, the junction of two of the teeth. The stone will thus at once grind the two converging edges of two contiguous teeth. Y

The cutter-bar may be held down by means of lugs h h, which project from that rib b against which the back edge of the cutter-bar is fitted, as shown.

When the stone gets smaller by wear its aXle Gr is lowered in the slots of the frame F, whereby the relative positions of the wheels f g are not changed, owing to the curved form of the slots.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. A machine for grinding thek sickles of harvesters, when consisting of the stationary frame A B, sliding frame F, and rotary grindstone H, the latter receiving its motion from a rotary shaft, D, by means of the rods K and signed by me this 23d day of November, 1868.

MILTON FWKS.` Witnesses FRANK BLoCKLEY, ALEX. F. ROBERTS. 

